Question What does code 0171 mean?

Avatoy · #1 (**permalink**) 03-26-2009, 04:33 PM

I've got this engine code of 0171, and I'm not sure exactly what it means. I've read other threads on O2 sensor or Air Flow/Fuel ratio sensors, and I thought it was my problem. My Avalon ran great for years on 87 octane, and then I got a check engine light. Several places couldn't pin it down to what exactly. One mechanic friend said it was my front air/fuel ratio sensor (bank 2, sensor 1), but he couldn't get it out. He said you would have to take the whole manifold out ($700), so I just switched to premium gas, and they seemed to do the job except some pinging in the summer while in the winter it ran perfectly. I let it go for 2 years, but now I worry that the pinging in the summer could damage the engine ( I was told this ) although the pinging only occurs when you really push it. In winter, it never pings. So I guess I need insight on what it could be, and what I should do. Thanks.

motech · #2 (**permalink**) 03-26-2009, 08:26 PM

what year model is the car and is p0171 the only trouble code and if it is what level is the long term fuel trim on both banks does the car have any hesitation when pressing the gas quickly

Avatoy · #3 (**permalink**) 03-26-2009, 10:21 PM

It is a 2000 Avalon, and it is the only trouble code, the car has no hesitation when pressing the gas quickly, and I don't know what "what level is the long term fuel trim on both banks" means. Thanks.

Avatoy · #4 (**permalink**) 03-26-2009, 10:48 PM

It is a 2000 Avalon, and it is the only trouble code, the car has no hesitation when pressing the gas quickly, and I don't know what "what level is the long term fuel trim on both banks" means. Thanks.

Avatoy · #5 (**permalink**) 03-27-2009, 04:41 PM

The code definition does say "air/fuel mixture lean on Bank 1."

motech · #6 (**permalink**) 03-29-2009, 11:34 PM

the majority of the time on this model car the p0171 code is caused by a dirty mass airflow meter but you can see the dirt if you remove it and look up inside of it there are two tiny wires that sense air flow if they get dirty it can cause this code but if you are not shure how to cheak this i would just take it to a shop or a dealer because it can still be a vaccume leak or clogged injectors or 02 sensor problems but most common is the mass air flow sensor

Avatoy · #7 (**permalink**) 03-31-2009, 04:21 PM

I cleaned the MAF sensor today, and after awhile I got another check engine light. My next step is to use something to clean the injectors. Anyone have any suggestions for a product for that purpose? Thanks again.